Russia said Monday it will extend the Black Sea Grain Initiative after it expires on March 18, but only for 60 days. The announcement came after consultations between U.N. representatives in Geneva and Russian Deputy Foreign Minister Sergei Vershinin.

"The Russian side, noting the package nature of the Istanbul agreements proposed by UN Secretary General António Guterres, does not object to another extension of the Black Sea initiative after the expiration of the second term on March 18, but only for 60 days," Vershinin said, according to Russian media reports.

Russia's consultations in Geneva on the grain deal were not easy, Vershinin said. Russia will rely on the effectiveness of the implementation of the agreement on the export of its agricultural products when deciding on a new extension of the grain deal, according to reports.

Ukraine, which is a key world exporter of wheat, barley, sunflower oil and fertilizer, had its shipments blocked in the months following the invasion by Russia, causing a worldwide spike in food prices. The first deal was brokered last July.

Russian forces suffered more than 1,100 dead in less than a week during battles near the eastern Ukrainian city of Bakhmut, the focal point of fighting in eastern Ukraine, President Volodymyr Zelenskyy said on Sunday.

During his nightly address, Zelenskyy described the battles as "Russia's irreversible loss."

Russian forces also sustained about 1,500 "sanitary losses," meaning soldiers were wounded badly enough to keep them out of further action, Zelenskyy said.

Dozens of pieces of enemy equipment were destroyed, as were more than 10 Russian ammunition depots, Zelenskyy said.

-ABC News' Edward Seekers

The investigation into who was behind the Nord Stream natural gas pipeline explosion should be "objective, impartial and transparent," Russian Foreign Minister Sergei Lavrov told Russian news agency Interfax.

"I do not want to threaten anyone. I do not want to hint at anything either. I just know that this flagrant terror attack will not go uninvestigated," Lavrov added.

Russia also said it will distribute its correspondence with Germany, Denmark and Sweden on the investigation of the Nord Stream explosion among the members of the United Nations Security Council soon.

Russia claimed the three countries are denying Russia access to information and participation in the investigation, first deputy permanent representative to the U.N. Dmitry Polyansky said in an interview, according to Russian news agency TASS.

-ABC News' Anastasia Bagaeva and Tanya Stukalova

Ukrainian President Volodymyr Zelenskyy denied that Ukraine had anything to do with the Nord Stream gas pipeline explosions last year.

"As for the Nord Stream, we have nothing to do with it," Zelenskyy said Friday.

The New York Times published a report that U.S. intelligence suggests that a pro-Ukrainian group sabotaged the pipeline.

Zelenskyy also suggested that the information being spread about the involvement of pro-Ukrainian groups in the attack could be done to slow down aid to his country.

-ABC News' Natalia Shumskaia

A top Russian pro-war blogger has been killed in a bomb attack on a cafe in Russia, according to police.

The explosion on Sunday tore through a cafe in St. Petersburg, killing Vladlen Tatarsky, one of the best-known of the Russian military bloggers who have become influential during the war in Ukraine.

At least 30 other people were injured in the blast, according to the Ministry of Health. Video circulating online appeared to capture the aftermath, showing bloodied people emerging from the heavily damaged cafe.

The Russian Interior Ministry said an explosion has occurred in a cafe on the city's Universitetskaya Embankment.

"One person was killed in the incident, it was military correspondent Vladlen Tatarsky, the Russian Interior Ministry press center told reporters on Sunday.

Denis Pushilin, acting head of the Russian-backed Donetsk People’s Republic, issued a statement describing Tatarsky as "a great patriot" of the Donbass region of eastern Ukraine and Russia. Pushilin blamed the attack on the Kyiv regime, calling it a terrorist regime.

"A man with a difficult fate, Vladlen earned the respect of his comrades-in-arms because he lived and worked for the sake of truth and justice, for the sake of victory," Pushilin said of Tatarsky. "He managed to fight, and in the status of a military correspondent to make his contribution."

Pushilin said Tatarsky was to be awarded a medal "for the liberation of Mariupol" in eastern Ukraine.

It was the most serious bomb attack on a pro-war Russian figure inside Russia since the high-profile assassination of the Daria Dugina, the daughter of the ultra-nationalist Alexander Dugina, who was killed in a car bombing last year.

Tatarsky was a Russian ultra-nationalist and one of the best-known military bloggers, who strongly supported the war in Ukraine. He had also criticized the execution of the war by Russia’s military command.

Tatarsky had become a significant source of information for how the war was being fought on the Russian side.

His killing will likely set off speculation on whether Ukraine or Russia was behind his killing, similar to the Dugina episode.

In the Dugina case, U.S. intelligence sources eventually told The New York Times that Ukraine was behind the attack.

-News Patrick Reevell